Levels and Curves adjustments are generally best done prior to conversion to monochrome.
Method 1 - Greyscale
- Image - mode - greyscale
Method 2 - Hue and Saturation
- Use hue/saturation control to desaturate to 100%
Method 3 - Double Hue and Saturation Layers
- Open a file and two hue/saturation adjustment layers .
- Desaturate the second (top) hue/saturation layer to minus 100%.
- Change the first hue/saturation layer to colour mode, and adjust the hue and saturation to give the required tonal balance.
Method 4 - Channel Mixing
- Use the adjust/channel mixing control.
- Tick the monochrome box.
- Adjust the colour channels to change the tones (the total of three channel percentages should usually be 100%).
Method 5 - Lightness Channel
- Open a file - image - mode - lab colour.
- Choose channels - select lightness channel.
- Image - greyscale - discard colour channels.
- Copy background layer - select blend (screen for dark image or multiply for light image) - adjust the opacity to achieve the required tone.
Method 6 - Selective Colour
- Open a file.
- Open new layer - fill with 50% grey - colour blend.
- Select the background layer - open selective colour adjustment layer - adjust the different colours to get right tonal balance.
Method 7 - Selective Colour
- Open a file
- Flatten the image.
- Create a new hue/saturation adjustment layer using saturation mode, hue = -180, saturation = -100 and lightness = +100
- Convert to LAB color and choose the flatten option if it is available.
- Open the channels window and delete channels A and B.
- Convert to greyscale.